Yield:447-93-8 61%

Reaction Conditions:

with isopentyl nitrite in N,N-dimethyl-formamide at 95 - 106; for 0.25 h;

Steps:

A.59.5

5) 3-Methoxy-4-trifluoromethyl-benzonitrile [CAS-no. 447-93-8]: The above prepared 2-amino-5-methoxy-4-trifluoromethyl-benzonitrile (7.08 g, 33 mmol) was dissolved in DMF (75 mL) heated up to 95° C., then slowly added isopentyl nitrite (6.75 mL, 49 mmol) dropwise by using a syringe, whereby the reaction temperature rose up to 106° C. (exothermic reaction). The reaction mixture was stirred for another 15 min at 95° C., then cooled rt, extracted with water and TBME, dried the organic layer over MgSO₄, filtered and the solvents evaporated. Purification by vacuum destillation at 1.6 mbar and 120° C. left a light yellow liquid, which still contained isoamyl alcohol and DMF and was therefore was purified by flash chromatography with n-heptane and ethyl acetate to give the 3-methoxy-4-trifluoromethyl-benzonitrile (4.0 g, 61%) as a colorless liquid. MS (EI) 201.1 [M⁺].

References:

US2007/232583,2007,A1 Location in patent:Page/Page column 39